16x2y-16x3-4xy2。
解:16x2y-16x3-4xy2
=4x(4xy-4x2-y2)
=-4x(4x2-4xy+y2)
=-4x(2x-y)2。
-- Tony, _________ is your father ?
-- He is a________.[ ]
A.Who, policeman
B.What, teacher
C.What, my uncle
D.Who, doctor